The present invention relates to a hatch closure assembly for use in filling railway covered hopper cars. More particularly, the present invention relates to a dust-tight hatch closure assembly having a filling means and a pneumatic seal means adapted to prevent the escape of dust during filling operations.
In the loading of particulate solids and powders through the hatches of a hopper car dusts are vented out the open hatchways and escape into the surrounding atmosphere. In addition to creating a nuisance and an air pollution problem, these dusts may become hazardous, forming explosive or flammable mixtures, thus endangering the safety of personnel and equipment. Methods for abating the venting of this dust into the atmosphere have included surrounding the fill tube, hopper or conduit and the hatch with a shroud formed of canvas or other flexible material, and providing the hatch with a lid frequently secured by clamping means and including a fill port or aperture to reduce the area available for venting dust. These methods require that the operator position the shroud or lid carefully and secure the shroud or lid in place with bolts or other clamping means to attain an effective closure, and are thus time consuming to employ and may be subject to inadequate operation through operator inefficiency and neglect.